1. Technical Field
This invention relates to a connector structure, and more particularly to a connector structure for connecting a connection end portion of a flat circuit member.
2. Related Art
Flat circuit members, such as a flexible printed circuit board (hereinafter referred to as xe2x80x9cFPCxe2x80x9d), formed by printing electrical conductors on an insulating film, and a flexible flat cable (hereinafter referred to as xe2x80x9cFFCxe2x80x9d) formed by covering a plurality of parallel conductors with an insulating material, have heretofore been extensively used in a wire harness, designed to connect electric parts in an automobile, and various equipments such as a computer since such a flat circuit member can be installed in a narrow space because of its construction, and also can be provided on a moving part because of its flexible nature.
Such a flat circuit member itself has flexibility, and therefore when the flat circuit member is to be connected to a connector, its end portion must be formed into a rigid terminal.
Therefore, there has been proposed a cable fixing method (disclosed, for example, in Japanese Unexamined Patent Publication Hei. 9-330772) in which there is used a cable holder for holding a distal end portion of an FFC. With this method, a cumbersome operation, in which a distal end portion of a cable is gripped and is inserted into a mating connector, is eliminated, and besides the incomplete insertion of the FFC and the incomplete locking of the connector are eliminated.
As shown in FIG. 9, the cable holder 100 includes a main holder portion 101 defining a holder body, and an auxiliary holder portion 102, and a distal end portion of the FFC 103 is held or fixed by these portions 101 and 102.
An insulating film or coating, covering conductors, is removed a predetermined length from one side of the distal end portion of the FFC 103 so as to provide a conducting portion 109 serving as a connection end portion. A reinforcing plate 105 including a thin resin plate is bonded to the other side of the distal end portion of the FFC 103. The distal end portion of the FFC 103, to which the reinforcing plate 105 is bonded, serves as a reinforcing portion 104, and notches 106 of a channel-shaped cross-section are formed respectively in opposite side edges of the reinforcing portion 104.
A recess 110, equal in width to the FFC 103, is formed in the main holder portion 101. Projections 107 of an elongate, convex shape, conforming in cross-section to the notches 106 in the FFC 103, are formed respectively on opposite side walls of the recess 110.
The auxiliary holder portion 102 is pressed or pushed into the recess 110 in the main holder portion 101 from the front side, and is fixed to the main holder portion 101. Therefore, grooves 108 of a channel-shaped cross-section, corresponding respectively to the projections 107, are formed in opposite side surfaces of the auxiliary holder portion 102, respectively. In order to retain the auxiliary holder portion 102 against disengagement, thus pushed into the recess 110 from the front side, retaining claws 111 are formed on the main holder portion 101 whereas notches 112 are formed in the auxiliary holder portion 102.
For attaching the FFC 103 to the cable holder 100 of the above construction, the notches 106 in the FFC 103 are registered respectively with the projections 107 on the main holder portion 101, and then the FFC 103 is pressed toward the bottom of the recess 110. Then, the grooves 108 in the auxiliary holder portion 102 are registered with the projections 107, respectively, and then the auxiliary holder portion 102 is pushed hard toward the main holder portion 101.
Then, when the auxiliary holder portion 102 is further pushed, the retaining claws 111 are engaged respectively in the notches 112, with a gap, corresponding to the thickness of the reinforcing portion 104, formed between the auxiliary holder portion 102 and the bottom of the recess 110. Therefore, the auxiliary holder portion 102 is fixed to the main holder portion 101 by the retaining claws 111, and cooperates with the main holder portion 101 to hold the reinforcing portion 104 therebetween in a fixed manner. In this condition, a stepped inner surface of a lower portion of the main holder portion 101 and a stepped inner surface of a lower portion of the auxiliary holder portion 102 jointly form a holder guide portion defining a space corresponding to an outer shape of the mating connector (not shown).
The FFC 103, thus held by the holder main potion 101 and the auxiliary holder portion 102 with the distal end portion thereof projecting into the holder guide portion, is firmly held against movement in the length of the cable since the projections 107 are engaged in the notches 106, respectively.
In the cable holder 100 of the above construction, however, the reinforcing plate 105 must beforehand be bonded to the FFC 103 so as to form the reinforcing portion 104 at the distal end portion of the FFC 103. Therefore, there are encountered problems that the efficiency of the assembling operation is low and that the production cost increases.
And besides, the notches 106 are formed in the opposite side edges of the reinforcing portion 104, respectively, and therefore in the case where the flat circuit member is an FFC having a plurality of parallel conductors covered with an insulating material, the conductors can not be provided at the opposite side portions of the cable, thus inviting a problem that the percentage of utilization of the flat circuit member is low.
Therefore, an object of the invention is to overcome the above problems, and more specifically to provide a connector structure in which a connection end portion of a flexible flat circuit member is easily formed into a terminal so as to be connected to a connector, and besides even when the connection end portion is formed into the terminal, the percentage of utilization of the flat circuit member is prevented from being lowered, and the stable connection performance can be obtained.
The above object of the invention has been achieved by a connector structure wherein a connection end portion of a flexible flat circuit member is inserted into a terminal receiving chamber in a connector housing, and conductors, exposed to the connection end portion, are electrically connected respectively to a plurality of connection terminals received in the terminal receiving chamber; CHARACTERIZED in that:
the connection end portion of the flat circuit member is provisionally held on obverse and reverse surfaces of a flat plate portion of a holder, which is to be fitted into the connector housing, in a folded-back manner, so that the conductors, provided on the connection end portion at predetermined intervals in parallel relation to one another, are arranged on the obverse and reverse surfaces of the flat plate portion; and
electrical connection portions of the connection terminals grasp the conductors, disposed on the obverse and reverse surfaces of the flat plate portion, respectively, so that the flat circuit member is electrically connected to the connection terminals.
In the above construction, the connection end portion of the flat circuit member, at which the conductors are exposed, is provisionally held on the flat plate portion of the holder in a folded-back manner, and then the holder is fitted into the connector housing, and merely by doing so, the conductors, disposed on the obverse and reverse surfaces of the flat plate portion, can be held respectively by the electrical connection portions of the connection terminals, received in the terminal receiving chamber, in a grasped manner, and therefore are electrically connected thereto.
Therefore, it is not necessary to bond a reinforcing plate to the connection end portion of the flat circuit member, and the efficiency of the assembling operation is enhanced. And besides, the connection end portion of the flat circuit member is held on the flat plate portion of the holder in a folded-back manner, and therefore can deal with a pulling force acting on the flat circuit member, so that the connection end portion is prevented from withdrawal.
Furthermore, the conductors on the connection end portion, held on the obverse and reverse surfaces of the flat plate portion of the holder in a folded-back manner, are electrically connected respectively to the electrical connection portions of the connection terminals in a grasped manner, and therefore each conductor contacts the associated connection terminal at two regions, so that the positive electrical connection can be achieved.
The above object of the invention has also been achieved by a connector structure wherein a connection end portion of a flexible flat circuit member is inserted into a terminal receiving chamber in a connector housing, and conductors, exposed to the connection end portion, are electrically connected respectively to a plurality of connection terminals received in the terminal receiving chamber; CHARACTERIZED in that:
the connection end portion of the flat circuit member is provisionally held on obverse and reverse surfaces of a flat plate portion of a holder, which is to be fitted into a holder casing which can be releasably inserted into the connector housing, in a folded-back manner, so that the conductors, provided on the connection end portion at predetermined intervals in parallel relation to one another, are arranged on the obverse and reverse surfaces of the flat plate portion;
the flat plate portion of the holder, having the connection end portion provisionally held on the obverse and reverse surfaces thereof, is passed through an insertion hole formed in the holder casing in which the holder is fitted; and
electrical connection portions of the connection terminals grasp the conductors, disposed on the obverse and reverse surfaces of the flat plate portion passed through the insertion hole, respectively, so that the flat circuit member is electrically connected to the connection terminals.
In the above construction, the connection end portion of the flat circuit member, at which the conductors are exposed, is provisionally held on the flat plate portion of the holder in a folded-back manner, and then the holder is fitted into the holder casing, and then the holder casing, receiving the holder, is inserted into the connector housing. Merely by doing so, the conductors, disposed on the obverse and reverse surfaces of the flat plate portion, can be held respectively by the electrical connection portions of the connection terminals, received in the terminal receiving chamber, in a grasped manner, and therefore are electrically connected thereto.
Therefore, it is not necessary to bond a reinforcing plate to the connection end portion of the flat circuit member, and the efficiency of the assembling operation is enhanced. And besides, the connection end portion of the flat circuit member is held on the flat plate portion of the holder in a folded-back manner, and therefore can deal with a pulling force acting on the flat circuit member, so that the connection end portion is prevented from withdrawal.
Furthermore, the conductors on the connection end portion, held on the obverse and reverse surfaces of the flat plate portion of the holder in a folded-back manner, are electrically connected respectively to the electrical connection portions of the connection terminals in a grasped manner, and therefore each conductor contacts the associated connection terminal at two regions, so that the positive electrical connection can be achieved.
When the holder is fitted into the holder casing, the flat plate portion of the holder, having the conducting portion provisionally held on the obverse and reverse surfaces thereof, is passed through the insertion hole formed in the holder casing, and therefore the conducting portion, disposed in contiguous relation to the obverse and reverse surfaces of the flat plate portion, is drawn through the peripheral edge of the insertion hole in a direction away from the folded-back portion toward the proximal end.
Therefore, even if the conducting portion of the flat circuit member should be disposed slightly off the surface of the flat plate portion of the holder, the conducting portion is drawn through the peripheral edge of the insertion hole, and therefore is brought into intimate contact with the obverse and reverse surfaces of the flat plate portion.
Preferably, that portion of the flat circuit member, disposed adjacent to the folded-back portion of the flat circuit member provisionally held on the obverse and reverse surfaces of the flat plate portion, is held between the holder and the holder casing in a bent manner.
In this case, even when a pulling force is applied to the flat circuit member, this tension is positively prevented from acting on that portion of the flat circuit member electrically connected to the connection terminals, so that the stable electrical connection performance can be achieved.